Computer printers are used with various host computers and with different software applications. When a new printer is introduced onto the market, users want it to work with the software applications they already own. However, previously existing software applications were written for previously existing printers. Problems arise when the new printer has new features, such as a higher resolution, because the existing software applications do not support the new features. For example, an old software application that was written to work with an old printer may only be able to create images at a low resolution. If a user attempts to print those images on a new, high-resolution printer, then the image will be distorted and dimensionally incorrect.
Currently existing inkjet printers do not address that problem and only support graphics in their own resolutions. When those printers are used to print graphics created under a lower resolution, the result is an image with a different size and aspect ratio than the original.
The invented method was designed to address those problems and was primarily developed for use in Hewlett-Packard's.RTM. DeskJet.RTM. printer. The use of the invention in the DeskJet.RTM. printer illustrates the method's utility.
To support previously existing software applications, the DeskJet.RTM. printer was designed to emulate existing printers such as the Epson FX-80 printer. A problem in creating the DeskJet's.RTM. emulation capability was that the basic print resolution of the DeskJet.RTM. is 300-dots-per-inch ("dpi") vertically and horizontally in a raster pattern. In contrast, the Epson FX-80 is a column-oriented graphics device with a vertical resolution of 72-dpi and selectable horizontal resolutions of 60, 72, 80, 90, 120 and 240-dpi. Thus, customized software had to be created to emulate the Epson FX-80. It should be noted that the Epson FX-80 emulation does not support all of the DeskJet's.RTM. features. The emulation was created so that existing software applications could work with a DeskJet.RTM. printer even though they did not support it.
The invented "Graphics Scaling Method for High Resolution Printers" was developed to accomplish that emulation. The method is applicable to any situation where it is desired that one printer emulate another printer of an equal or lower resolution. Thus, the invented method overcomes the problem of image distortion when an image is created for one printer but actually printed on a different, higher-resolution printer.